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INTEGRAL News archive for 2007
20 December 2007 In order to maintain the SPI high spectral resolution, a new SPI annealing period has been agreed. The 11th annealing will start in Revolution 641 (i.e., January 12, 2008) and will have a duration of about 6 revolutions.
17 December 2007 With its powerful detectors, INTEGRAL has performed the most-sensitive all-sky survey ever, finding expected clumpy areas at large scales in our local universe. Scientists working with ground-based telescopes have found the same local clumps, while looking for sources of cosmic showers.
INTEGRAL performed the survey in the hard X-ray band of the electromagnetic spectrum. Although it wasn't the first such survey, INTEGRAL's strength lies in the fact that it is unbiased towards sources that are shrouded by dust or gas, invisible at optical and soft X-ray wavelengths.
An interesting correlation has been found in data collected with the Auger telescopes in Argentina. Such a correlation with optical data is opening a new door in the exploration of the local universe.
Looking around, our neighbouring local universe is fairly homogeneous. However, a lot of 'clumps' or structures are found at smaller scales, less than 100 megaparsecs or about 326 million light years.
Scientists believe that as the early universe expanded and grew, small perturbations introduced later formed structures confined to smaller spatial scales, leaving the universe homogeneous on scales larger than 100-200 megaparsecs (about 326 million to 652 million light years). INTEGRAL has confirmed just this.
For more information, see the ESA Space Science News: Understanding our neighbourhood in the universe
05 December 2007 The deadline (30 November 2007) for submission of INTEGRAL proposals for "Key Programmes" (KP) for the AO-6 cycle of observations has been passed.
19 November 2007 Following an earlier recommendation from the INTEGRAL science working team (ISWT) a sequential rotation covering the range +-3 degrees between successive repetitions of the same (5x5) pattern has been implemented by ISOC. The goal of this rotation is to reduce systematic errors in deep mosaic images of ISGRI data. With this strategy, implemented from 24 November 2007 (rev. 624), the roll angle for an observation with N repetitions of the 5x5 pattern shall span the range from +3 deg to -3 deg, in steps of dtheta = 6/(N-1).
13 November 2007 During its meeting on 12/13 November, the ESA's Science Programme Committee (SPC) has unanimously approved to extend the mission operations for INTEGRAL and XMM-Newton until 31 December 2012. For more information, see the ESA Space Science News: Extension of ESA's Integral and XMM-Newton missions approved
07 November 2007 Astronomers from around the world have been discussing the extraordinary scientific riches that have flowed from ESA's orbiting gamma-ray observatory, INTEGRAL. Here we present the gist of some of the astonishing ones.
When INTEGRAL was launched in 2002 it was intended to take detailed gamma-ray images and spectra of the universe and to look for new types of sources in this relatively unexplored field. In all these objectives, it has excelled.
INTEGRAL discovers about 100 new gamma-ray sources a year, says one of the conference organisers, Angela Bazzano, Istituto di Astrofisica Spaziale e Fisica Cosmica, Roma. These objects are spread throughout the Universe.
Its instruments have been fine-tuned to the so-called soft gamma-ray band, where the majority of celestial gamma rays are emitted. It has used these instruments to identify some of the most puzzling sources of celestial gamma rays. These Tera electron Volt (TeV) sources were first seen from telescopes on Earth looking for the brief flash of light that occurs when highly energetic gamma rays enter the atmosphere.
For more information, see the ESA Space Science News: New scientific riches from INTEGRAL
22 october 2007 Today, the Director of the Scientific Programme (Prof. David Southwood) has released the Announcement of Opportunity for Key Programme (KP) observing proposals for the AO-6 Cycle of observations with INTEGRAL. This announcement solicits proposals for observations to be caried out in the period from August 2008 to August 2009. Proposers from all over the world are welcome to participate. All proposals will be subject to an independent peer review by the INTEGRAL Time Allocation Committee (TAC). The deadline for Proposals submission is 30 November 2007, 15.00 CET.
More information can be found under the AO-6 Key Programme section.
17 October 2007 In this issue of the ISOC Newsletter:
Read more in the ISOC Newsletter #18.
17 October 2007 With eyes that peer into the most energetic phenomena in the universe, ESA's INTEGRAL has been setting records, discovering the unexpected and helping understanding the unknown over its first five years.
INTEGRAL was launched on 17 October 2002. Since then, the satellite has helped scientists make great strides in understanding the gamma-ray universe - from the atoms that make up all matter, giant black holes, mysterious gamma-ray bursts to the densest objects in the universe.
For more information, see the ESA Space Science News: Science with INTEGRAL - five years on
11 October 2007 The final Scientific Programme of the Workshop "FIVE YEARS OF INTEGRAL" is available from this site.
03 October 2007 There is a gamma-ray lighthouse shining from the edge of our universe. Astronomers have discovered it using ESA's orbiting gamma-ray observatory, INTEGRAL. Now, they must work hard to understand it.
The object, known only by its catalogue name IGR J22517+2218, was discovered this year, but its nature was unknown. This is not an unusual situation. Around 30% of the sources discovered by INTEGRAL remain unidentified so far. All astronomers know for certain, is that there are celestial sources out there, pumping gamma rays into space. However, the identification of the sources with individual celestial objects will have to wait for more detailed observations in other wavelengths.
For more information, see the ESA Space Science News: Gamma-ray lighthouse at the edge of our universe
31 August 2007 ISOC is preparing the release of the Announcement of Opportunity for Key Programmes to be executed in AO-6. Key milestones are shown below.
30 August 2007 The collection of abstracts submitted for the Workshop "FIVE YEARS OF INTEGRAL" is available from this site.
05 July 2007 The INTEGRAL AO-5 General Programme, as recommended by the Time Allocation Committee and approved by the Director of the Scientific Programme (Prof. David Southwood) has been released.
25 June 2007 ESA's orbiting gamma-ray observatory, INTEGRAL, has made a pioneering unequivocal discovery of radioactive iron-60 in our galaxy that provides powerful insight into the workings of massive stars that pervade and shape it.
Found drifting in space, the radioactive isotope has been sought for long. All past reported sightings of iron-60 have been subject to controversy. Now INTEGRAL has provided unequivocal evidence.
Since late 2002, INTEGRAL has been collecting data from across the galaxy. It shows an enhancement in gamma rays at two characteristic energies, 1173 and 1333 kilo electron Volts. These are produced by radioactive decay of iron-60 into cobalt-60.
Roland Diehl of the Max-Planck-Institut für extraterrestrische Physik, headed the work and believes it is a major step forward. "These gamma-ray lines have been detected before with some dispute. Integral, the only instrument capable of doing this, shows that iron-60 does exist in interstellar space in our Galaxy," he says.
More than a curiosity, its presence opens a door into the very heart of the most massive stars in the cosmos. The majority of chemical elements are built inside stars from raw ingredients present during star formation from an interstellar gas cloud. In addition to hydrogen and helium produced during the Big Bang, the gas contained enrichments, known to astronomers as 'metals', from previous generations of stars and their nuclear reactions.
For more information, see the ESA Space Science News: Radioactive iron, a window to the stars
11 May 2007 The ESA INTEGRAL mission successfully performs observations of the high-energy sky since its launch on October 17, 2002. We plan to celebrate this at INTEGRAL's 5th anniversary with a 3-day science workshop in Sardinia/Italy on October 17-19, 2007.
The workshop will be organized in sessions dedicated to the topics of
Also, INTEGRAL's Achievements and its Mission Perspective will be addressed by additional talks from INTEGRAL team members.
This workshop will be informal and dedicated to scientific discussions. Presentations will be made publicly available, but no Proceedings book will be generated. For more details on the workshop see the conference web site
Your INTEGRAL 5th Anniversary Workshop Organization Team,
25 April 2007 The deadline (20 April 2007) for submission of INTEGRAL proposals for AO-5 open time observations is now a few days behind us. All proposals are in the ISOC database. Below are some preliminary statistics on the proposals that have been received.
Total number of proposals
In the AO-5 three "Key Programme" observations, of the Galactic Centre region, North Ecliptic Pole and Cygnus region, for a total of 6 Msec were included in this Call, and scientists were also invited to submit proposals for the data analysis of scientific targets located in these regions. A total number of 85 proposals (included in the total of 160 received proposals), associated with the "Key Programmes", was received. These associated proposals do not require additional observatory time.
Proposals per category
Numbers for proposals associated with the Key Programme, not requesting observing time, are given in brackets
N = number of proposals
The Time Allocation Committee, whose purpose is to peer review all proposal s and recommend a scientific observing programme to ESA, will meet from May 29 to June 1 at ESTEC. Following this meeting, ESA will announce the approved programme for AO-5, which will begin on August 16, 2007.
16 April 2007 PGT was updated to fix a bug in printing coordinates. This bug does not affect delivery of proposals to ISOC, but proposers willing to download the latest version (v5.5) can find it here
12 March 2007 Today, the Director of the Scientific Programme (Prof. David Southwood) has released the Announcement of Opportunity for AO-5 Cycle Observation Proposals and for obtaining Data Rights to targets within previously approved Key Programmes. This announcement solicits proposals for observations to be caried out in the period from August 2007 to August 2008. Proposers from all over the world are welcome to participate. All proposals will be subject to an independent peer review by the INTEGRAL Time Allocation Committee (TAC). The deadline for Proposals submission is 20 April 2007, 14.00 CET.
More information can be found on the AO-5 page.
03 March 2007 The INTEGRAL Science Operations Centre (ISOC) Newsletter #17 has been published with the latest news on:
Read more in the ISOC Newsletter #17.
20 February 2007 INTEGRAL's latest survey of the gamma-ray universe continues to change the way astronomers think of the high-energy cosmos. With over seventy percent of the sky now observed by INTEGRAL, astronomers have been able to construct the largest catalogue yet of individual gamma-ray-emitting celestial objects. And there is no end in sight for the discoveries.
INTEGRAL is the European Space Agency's latest orbiting gamma-ray observatory. Ever since INTEGRAL began scientific operations in 2003, the project team has been devoting a substantial proportion of its observing time to a survey of the gamma-ray universe.
"The gamma-ray sky is notoriously variable and extremely unpredictable," says Anthony Dean, University of Southampton, UK, one of the original proposers of the INTEGRAL mission. Hence, the need for INTEGRAL's constant vigilance and an accurate catalogue of all gamma-ray sources. With this, astronomers can target individual gamma-ray objects for more detailed, study.
For more information, see the ESA Space Science News: INTEGRAL expands our view of the gamma-ray sky
16 February 2007 Astronomers using ESA's gamma-ray observatory, INTEGRAL, have detected what appears to be the fastest spinning neutron star yet. This tiny stellar corpse is spinning 1122 times every second. If confirmed, the discovery gives astronomers the chance to glimpse the insides of the dead star.
The neutron star, known by its catalogue number XTE J1739-285, was discovered during one of its active phases on 19 October 1999 by NASA's Rossi X-Ray Timing Explorer (RXTE) satellite. In August 2005, while INTEGRAL was monitoring the bulge of the Galaxy, XTE J1739-285 started to come back to life. About a month later INTEGRAL discovered the first short bursts of X-rays from the object.
For more information, see the ESA Space Science News: INTEGRAL points to the fastest spinning neutron star
06 February 2007 INTEGRAL has scheduled the following ToO observation:
Start time Rev Time (s) Source RA (J2000) Dec.(J2000) 2007-02-17 18:50:59 531 93600 GX 339-4 17:02:49.50 -48:47:23.0 2007-02-18 22:37:36 531 20800 GX 339-4 17:02:49.50 -48:47:23.0
For more details we refer to the INTEGRAL short-term plan on the web.
As announced in The Astronomer's Telegram #980, INTEGRAL is performing these ToO observations as part of a campaign on GX 339-4 (PI: Miller), which started on Jan 30, 2007. 130 ksec observations will be done each approximately every 2 weeks for the coming two months. See the long-term plan for the current schedule.
The INTEGRAL data will be made publicly available, as soon as possible after the observations have been performed. They can be retrieved from ftp://isdcarc.unige.ch/arc/FTP/arc_distr/GX339-4/
The observation to be performed on Feb 17-19 and the next 2 sets of INTEGRAL observations will be done simultaneously with ~10 ksec XMM-Newton observations. Data from the latter observations will also be made public.
Erik Kuulkers, ISOC
18 January 2007 ESA's gamma ray observatory INTEGRAL has caught the centre of our galaxy in a moment of rare quiet. A handful of the most energetic high-energy sources surrounding the black hole at the centre of the Galaxy had all faded into a temporary silence when INTEGRAL looked.
This unusual event is allowing astronomers to probe for even fainter objects and may give them a glimpse of matter disappearing into the massive black hole at the centre of our galaxy.
For more information, see the ESA Space Science News: INTEGRAL sees the Galactic centre playing hide and seek